45．A．No one                B．Everyone             C．Someone

（A）

As space science develops, man has learned more and more about space．Space is not only amazing but also dangerous．While working in space, spacemen are facing danger as well as Success．

Scientists have found out that radiation(辐射)is the greatest danger to spacemen in space．When space men are working in space, they are in danger of radiation from the sun and other stars, which is bad for their health．The damage(危害)done by radiation won’t be discovered until their children or even grandchildren are born．Some special medicine may work a little, but no really helpful medicine mas been．

Space junk(垃圾)is also thought a great danger to spacemen．It's reported that there are 9,000 man-made things flying in space．About 30％of these are satellites(卫星), 10％are spaceships, and the rest are space junk．An explosion(爆炸)in l996 made a cloud of 300,000 fragments, each at least 4ram in size, and even a small piece of these knocked against a spaceship window and did some damage．Scientists are watching and reporting any possible danger all the time．They are working on helpful ways to do with space junk．

Although space is really dangerous, it interests everyone on the earth．In the near future, it may become usual for people to spend a few days in a space hotel．We may even choose to leave the earth and live in space in a few years．So we should care for space and do something to help improve the space environment．

根据短文内容选择最佳答案。

44．A．will                     B．won’t                         C．would

43．A．happy                  B．sad                      C．comfortable

42．A．with                    B．to                        C．of

41．A．or                       B．and                     C．but

40．A．where to do         B．how to do            C．what to do

39．A．every                         B．all                       C．both

38．A．one                      B．ones                    C．the ones

37．A．fail                     B．win                     C．know